The present disclosure relates to light emitting diodes and more particularly to reflective coatings for light emitting diodes and light emitting diodes with reflective coatings.
Light emitting diodes are used in many applications including indicator lights, as backlighting for liquid crystal display panels for television sets, monitors, and other displays, automotive lighting and other lighting. LEDs are also becoming much more popular as general illumination devices. The demand for LEDs is growing. The demands on LEDs are growing. LEDs are expected to operate reliably for long periods of time. LEDs are expected to maintain consistent light output over extended periods of time. In many applications LEDs are expected to maintain light output over years or decades.
LEDs are often used in structures or situations in which there is a preferred direction of light emission. Thus, if a light emitting diode is mounted on a structure behind a liquid display, the preferred direction of light emission is toward the liquid crystal array. If a light emitting diode is on a control panel, the direction of preferred lighting is toward the person viewing the panel. Light emitting diodes often have reflective coatings on the surface away from the direction of preferred light emission. In the past, some of these coatings have been pure silver. Pure silver is prone to environmental degradation which can adversely affect the reflective and adhesive properties of the coating.